Evaluation beyond convolutional image-classification covariance heads

Investigate the decomposition-free polynomial matrix-logarithm normalizer in second-order transformer heads, partial-correlation representations, higher-order spectral iterations, and dense-prediction settings, where covariance dimensions and spectral distributions may differ from those evaluated for convolutional global covariance pooling.

Background

The paper evaluates the proposed decomposition-free logarithmic normalizers only for image classification using a convolutional global covariance pooling head with covariance dimension d=256. It identifies second-order transformer heads, partial-correlation representations, higher-order spectral iterations, and dense prediction as settings in which the method could serve as a drop-in normalization replacement but has not yet been evaluated.

The authors specifically note that the spectral fitting interval may need to be re-estimated in these settings because covariance dimensions and spectral shapes can differ. The paper therefore leaves empirical validation of the method across these application classes as future work.

References

We leave these, with dense prediction and a Schur--Padé error analysis of the reverse recurrence, to future work.

Orthogonal Polynomial Approximation for Matrix Log Normalization in Global Covariance Pooling  (2608.19021 - Rahman et al., 19 Aug 2026) in Section Conclusion, paragraph “Limitations”